Resilient mounting for abrasive wheels



3W0 L. RESILIENT MOUNTING FOR ABRASIVE WHEELS Filed April 29, 1939 INVENTOR 8401 L. I'fflZ/V/C/f WW9" ATTORNEY lO .,/6 v

working position; and

' utented Jan. 16, 1940 RESILIENT MOUNTING FOR ABRASIVE WHEELS Paul L. Kumiick, Clifton, N. J., assignor to Raybestos-Manhattan, Inc., Passaic, N, J., a corporation of New Jersey Application April 29, 1939, Serial No. 270,771

Ulaims. (01. 51-168) This invention relates to a resilient mounting for abrasive wheels.

Resilient mountings for abrasive wheels have been heretofore suggested and tried, but have been used only to a very limited extent because of the mechanical difficulties encountered and because oi the expense of properly adapting such mountings to working conditions.

The principal object of my present invention relates to the provision of a resilient mounting which will provide a complete cushioning for and insulation of the wheel from the grinder parts (i. e., from the spindle and the clamping flanges), and yet produce a centered, firm, and stable mounting for the wheel. With the grinding wheel thus completely insulated and cushioned from and yet properly centered and firmly and stably mounted on the grinder, surprising results are achieved. On a portable grinder the life of the wheel is substantially lengthened, a finer grinding finish of the work is obtained, fatigue of the worker is reduced, the life of the grinder itself is increased, and the risk of wheel breakage is sharply minimized.

A corrolary object of the invention resides in the provision of a resilient mounting so designed and constructed as to permit ready and facile attachment thereof to the abrasive wheel and quick and simple mounting of the abrasive wheel on the grinder, whereby the desired coordinated results are accomplished by a device which readily adapts itself to the mechanical elements involved and to the working conditions normally met with in practice.

To the accomplishment of the foregoing, and the other objects which will hereinafter appear, the invention consists in the resilient mounting as hereinafter more particularly described in the specification and sought to be defined in the claims. The specification is accompanied by a drawing, in which: 7

Figure l is a perspective view of the elements comprising the resilient mounting of the present invention;

Figure 2 is a view mainly in cross-section showing the resilient mounting applied to a portable grinder and showing the relation of the parts prior to clamping the wheel in position;

Figure 3 is a similar view thereof showing the relation of the parts with the wheel clamped in Figure 4 is a perspective view of an element of a modification of the resilient mounting.

Referring now more in detail to the drawing, having reference first to Figure .1 thereof, the resilient mounting of the invention comprises a resilient member made, for example, of a flexible and compressible rubber, generally designated as l0, having a bushing part I2 insertible into the mounting hole of an abrasive wheel and receivable by the grinder spindle, and integral disc parts I4, l4 radiating from the bushing part l2 at opposite ends thereof, each disc part being arranged to be clamped between the side face of the abrasive wheel and the adjacent grinder clamping flange. While this resilient mounting device may be made in one piece, it is a feature of the invention to produce the same in two mating pieces, one insertible into one side and the other into the other side of the abrasive wheel, these pieces being preferably made identical in form so that twin pieces are used to make up a complete mounting. This is clearly shown in Figure 1 of the drawing, the twin pieces being designated therein as Ill and HP, each comprising the bushing part l2 and the integral radiating disc part 14.

In a resilient mounting of this nature, certain tolerances are necessary to allow the bushing part to fit loosely between the hole of the grinding wheel and the mounting spindle. With this locseness, however, it is difl'icult to properly center the wheel and to hold the wheel stably centered during its rotation and application to the work. To solve this problem, there is provided in the resilient mounting a compression part which is adapted to be contacted and compressed by the grinder flange for expanding the bushing part radially into tight engagement with both the grinder spindle and the wall of the wheel hole, so that there is produced a centered, firm, and stable mounting for the wheel which is thus completely cushioned on the grinder. This is accomplished by the provision of a compression bead I6 preferably for each mounting piece, which protrudes axially from the bushing part I2 and which is adapted to be engaged and compressed by the grinder flange to cause the radial expansion of the bushing part into engagement with the spindle and wheel.

In Figures 2 and 3 of the drawing, the resilient mounting of the invention is shown applied to a portable type of grinder, FigureZ showing the relation of-the parts before the wheel is clamped in position and Figure 3 showing the relation of the parts when the wheel is clamped in working position. As will be evident from Figure 2 of the drawing, the mounting pieces ill and tu are first attached to the wheel before the wheel is mounted on the grinder, and this is accomplished by the simple step of inserting the bushing parts 92, ii of the mounting pieces ill and W into the mounting hole l8 of the grinding wheel 2th from opposite sides of the wheel. After this is done, the wheel with the resilient mounting pieces thereon is slipped on to the spindle 22 of the grinder 24 into position to be clamped between the usual clamping flanges 26 and 28, the clamping being effected by the rotation of the nut 30 on the threaded end 32 of the spindle 22. To enable the facile and ready insertion of the mounting pieces into the grinding wheel hole and the ready reception of the wheel and the mounting pieces by the spindle 22, it is apparent that certain tolerances must be allowed in the fit between the resilient bushings l2, I2 and the wall of the wheel hole I8 as well as the surface of the grinder spindle 22. These tolerances are indicated by the clearances or spaces 34 and 36, respectively. Unless these spaces are effectively closed, it is found that the wheel is not properly centered and cannot be held or maintained centered during rotation and. application to the work. To firmly support and clamp the wheel radially as well as axially, and yet to provide a complete cushioning insulation of the wheel on the grinder, the clearances or spaces 34 and 36 should be filled when the wheel is clamped in position. It ,is to this end that the compression beads l6, l6 are provided, these compression beads being constructed to protrude axially from and form in effect an external continuation of the bushing parts l2 so that they may be engaged by the clamping flanges 26 and 28 before these clamping flanges contact with or engage the disc parts ll, of the resilient mounting, such relation of the parts being best depicted in Figure 2 of the drawing.

Referring now to Figure 3 of the drawing, it will be seen that when the nut 30 is screwed home to tighten the clamping flanges 26, 28, the beads IS, IS are compressed with the result that the bushings I2, l2 are expanded radially in opposite directions to fill up the clearances or spacings (34 and 36) between the same and the wheel hole and spindle, respectively. The excess material of the compression beads l6, i6 is free to flow in the dished space 38 within the rim 40 of each clamping flange, as clearly shown in Figure 3 of the drawing, thus permitting the rims 40, 40 of the clamping flanges to securely engage the disc parts I4, I! of the resilient mounting pieces.

Therefore, by means of this construction, wheel 20 is firmly supported not only axially between the rim as well as the hub sections of the clamping flanges, but also radially along the full supporting length of the grinder spindle, producing thereby a complete cushioning support and insulation for the wheel and a centered, firm, and

stable mounting therefor. It will also be evident that by me." ns of the construction provided, ready and facile attachment of the mounting pieces to the abrasive wheel, as well as quick and simple mounting of the abrasive wheel on the grinder, are afforded whereby the desired coordinated results are accomplished by simple and inexpen- I sive means.

The resilient mounting l0 may, if desired, be made in one piece, but it will be obvious that the making of the same in twin sections allows the greatest facility in placing these on the wheel and also permits the taking care of varations in the nature of common tolerances in the thicknesses of given size wheels, While I prefer to make the resilient mounting of a flexible and soft rubber material, it will be apparent that other materials may be employed.

In Figure 4 of the drawing, I show a modification which is designed to prevent radial stretch and creep of the disc part of the resilient mounting elements. This is accomplished by the use of a metal perforated disc 42 molded into one side (preferably the flange engaging face) of the disc part i l of the resilient mounting element. By means of this perforated disc there is prevented the stretch and creep of the disc part l4, should any radial force exist as in the case of wheel rupture, the said perforated disc serving thereby to prevent the loosening of the complete assembly.

The resilient mounting of the present invention has been found most serviceable when used on portable grinders, althoughit has been used to great advantage on other types of grinding machines such as stand grinders and swing frame grinders. When used with portable grinders, the life of the wheel is substantially lengthened, a finer grinding finish of the work is obtained, fatigue of the worker is reduced, the life of the grinder itself is increased, and the risk of wheel breakage is sharply minimized. The wheel life is increased by reason of the reduced pounding of the wheel against the work. It is well known in grinding practice that excessive pounding of these portable grinders causes undue stress on the abrasive particles, resulting in rapid'breakdown of grain and structure before the abrasive particles have fully completed their usefulness. I have found that in rubber bonded wheels, thewheel life is increased nearly twofold, and that with resin bonded wheels, the wheel life is increased almost fourfold when the rubber mountings of the present invention are employed. The obtaining of a finer finish to the work is due to a reduction of the vibration and a reduction of the breakdown of the grinding wheel face. It is found that the resilient mountings absorb'and dampen vibration caused by wheel out-of-balanoe, wheel truth, or machine conditions and motions which are set up in the machine when it is applied to the work. The absorption of vibrations, shock, and pounding of the wheel when used on portable grinders reduces the fatigue of the worker. As a corrolary to these results, it has been found that the life of the grinding machine itself is greatly increased. It is a known fact that shocks resulting from wheel contact to work can break a grinding wheel, especially if it is made of a more or less brittle bond. These shocks being effectively absorbed by the resilient mounting device of the present invention, the chances for wheel breakage are sharply curtailed.

The construction and functioning of the resilient mounting of the present invention and the many advantages thereof will be fully apparent from the above-detailed description. It will be further apparent that while I have shown the preferred form of constructing the resilient mounting, changes may be made in the structure and form thereof without departing from the spirit of the invention defined in the following claims.

What I claim is:

1. A resilient mounting for abrasive wheels comprising a resilient member having the following parts: a bushing part loosely insertible into the mounting hole of the abrasive wheel and loosely receivable by the grinder spindle, a disc part radiating from the bushing part and arranged to be clamped between the side face of the wheel and the grinder clamping flange, and a compression part extending outwardly from the bushing part adapted to be contacted and compressed by the grinder flange for radially expanding the bushing part into tight engagement with the wheel hole and the grinder spindle.

2. A resilient mounting for abrasive wheels comprising a flexible and resilient member having I the following parts: a bushing loosely insertible into the mounting hole of the abrasive wheel and loosely receivable by the grinder spindle, a disc radiating from the bushing and arranged to be clamped between the side face of the wheel and the grinder clamping flange, and a compression bead axially protruding from the bushing adapted to be contacted and compressed by the grinder flange for radially expanding the bushing into tight engagement with the wheel hole and the grinder spindle.

ii. A resilient mounting for abrasive wheels comprising two mating resilient members one insertible into one side and the other into the other side of the wheel and each having the following parts: .a bushing part loosely insertible into the mounting hole of the abrasive wheel and loosely receivable by the grinder spindle, a disc part radiating from the bushing part and arranged to be clamped between the side face of the wheel and the grinder clamping flange, and a compression part extending outwardly from the bushing part adapted to be contacted and compressed by the der flange for radially expanding the bushing part into tight engagement with the wheel hole and the grinder spindle.

4. A resilient mounting. for abrasive wheels comprising a resilient member having the following parts: a bushing part loosely insertible into the mounting hole of the abrasive wheel and loosely receivable by the grinder spindle, a disc part radiating from the bushing part and arranged to be clamped between the side face of the wheel and the grinder clamping flange, and a compression part extending outwardly from the bushing part adapted to be contacted and compressed by the grinder flange for expanding the bushing part into tight engagement with the wheel hole and the grinder spindle; the disc part of the said resilient member being'provided with a metallic insert to control the radial stretch thereof.

5. A resilient mounting for abrasive wheels comprising a bushing member loosely insertible into the mounting hole of the abrasive wheel and loosely receivable by the grinder spindle, disc members radiating from the bushing member,

each disc member arranged to be clamped between the side face of the wheel and the grinder clamping flange, and compression members extending outwardly from the opposite ends of the bushing member adapted to be contacted and compressed by the grinder flanges for radially expanding the bushing member into tight engagement with the wheel hole and the grinder spindle.

PAUL L. KUZMICK. 

